This invention relates to displaying the process used by a pulse oximeter for identifying the maximum and minimum values of pulsatile waveforms in order to determine the amplitudes used for calculating oxygen saturation.
The oximetric measurement of oxygen concentration in blood has been a valuable tool since it became commercially available in the United States in the early 1970's. Generally, an oximeter is a photoelectric instrument that continually measures the oxygen content of blood or oxygen saturation in a person by measuring the intensity of a light beam transmitted through body tissue. Oxygen saturation is numerically displayed as a percentage, and is typically accompanied by an audible alarm if the current value is outside preset limits of acceptable saturation.
Early oximeters used many wavelengths of light to describe quantitatively the concentrations of hemoglobin components of blood, but cost and size constraints limited their acceptance in the marketplace. More recently, with the introduction of pulse oximetry, which requires only that the sensor be used in an area of pulsatile blood flow, cost and size restraints were greatly reduced. This new generation of pulse oximeters have found overwhelming acceptance due to the critical importance of oximetry during anesthesia.